Systems chemistry approach to polyhexahydrotriazine polymeric structures

ABSTRACT

In some embodiments, a product, such as a thermoset, has a polyhexahydrotriazine and a self-polymerized cross-linkable polymer. In some embodiments, a product is the reaction product of a diamine, an aldehyde, and a compound having an α,β-unsaturated electron withdrawing moiety.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 14/951,186 filed Nov. 24, 2015. The above-mentioned application ishereby incorporated by reference.

FIELD

Embodiments herein generally relate to polyhexahydrotriazines (PHTs)with tailored macromolecular architectures.

BACKGROUND

Polyhexahydrotriazines (PHTs) are an emerging class of high strengthengineering thermosetting polymers (thermosets) that have a uniquecombination of properties. PHTs have high modulus, solvent resistance,and resistance to environmental stress cracking. The ability to tuneboth the thermal and mechanical properties of PHTs is critical to meetthe increasingly stringent demands of structural materials. Addition ofa second polymer to a PHT network is one method of tuning the thermal ormechanical properties of a PHT network, but such multicomponent PHTnetworks suffer from biphasic separation of the individual polymers andmultistep syntheses are required in order to obtain each type of polymerfor the PHT network.

Therefore, there is a need in the art for PHT networks andmulticomponent PHT networks with improved material properties, andimproved syntheses of these networks.

SUMMARY

In some embodiments, a product has a polyhexahydrotriazine and aself-polymerized cross-linked polymer.

In some embodiments, a product is the reaction product of a diamine, analdehyde, and a compound having an α,β-unsaturated electron withdrawingmoiety.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph illustrating relative glass transitions (reversingheat capacity) obtained after curing the films at 200° C.

FIG. 2 is a graph illustrating relative glass transitions (reversingheat capacity) obtained after curing the films at 200° C.

DETAILED DESCRIPTION

Embodiments herein generally relate to polyhexahydrotriazines (PHTs)with tailored macromolecular architectures. New PHT materials withtailored macromolecular architectures and their methods of preparationare disclosed. In particular, the new PHT materials may serve as athermoset for polymer pre-impregnated mat (pre-preg) and forlight-weight and high strength composites in the fields of electronics,automotive, and aerospace. To that end, a systems chemistry approach maybe used to synthesize PHT materials that achieve tunable materialproperties such as yield strength, char yield, and thermal response. Asystems chemistry approach allows for access to tunable propertiesthrough the directed application of isolated and/or inter-relatedchemical reactions, simultaneously in a single vessel. The chemicalreactions described herein may, however, also be performed individuallyin separate vessels, where products, which may be thermosets, are thenformed by mixing (and optionally curing) the isolated polymer reactionproducts. Nonetheless, in the context of PHT materials, a systemschemistry approach allows mitigation of some of the challenges forrecyclable high-performance thermosetting hexahydrotriazinesconveniently by incorporating functional groups that promote the desiredmaterial properties in a single step through judicious choice ofpolymers and/or co-polymers based on reactivity.

In some embodiments, a thermoset has a polyhexahydrotriazine and aself-polymerized cross-linked polymer. The self-polymerized cross-linkedpolymer may be selected from polycyanate, polyalkyne, and polyimide. Insome embodiments, the product further comprises a poly(amine-imide)copolymer. As described herein, the term ‘copolymer’ includes a polymerderived from more than one species of monomer. The poly(amine-imide)copolymer may be of the structure:

where R is selected from the group consisting of ether, aryl, and alkyl,X is a phosphine derivative, ether, or lactone. The length of polymersdescribed herein is limited to the polymerization of monomers and/orviscosity of reaction mixtures (vitrification). The present disclosureis meant to cover all such polymers. Typically, n is a positive integer,such as from between about 2 to about 500, such as between about 2 andabout 100, such as between about 10 and about 50. In some embodiments,the product further comprises a copolymer having a conjugate additionproduct, such as a Michael-adduct, and a hexahydrotriazine moiety. Theproduct may further comprise a self-polymerized compound, polymerizedfrom a compound having an α,β-unsaturated electron withdrawing moiety(i.e., an acceptor), such as a Michael acceptor. As used herein, theterm “acceptor” means a compound having an α,β-unsaturated electronwithdrawing moiety. The self-polymerized acceptor may be of the formula:

where R is ether, aryl, or alkyl, and n is a positive integer, such asfrom between about 2 to about 500, such as between about 2 and about100, such as between about 10 and about 50. In some embodiments, theproduct further comprises a copolymer having a self-polymerized compoundformed by an α,β-unsaturated electron withdrawing moiety beforepolymerization, such as a Michael acceptor, and an amino reacted adductof a compound having an α,β-unsaturated electron withdrawing moietybefore, such as a Michael adduct. The product may also have across-linked copolymer. In some embodiments, the product has apoly(aminoalcohol).

In some embodiments, a product is the reaction product of a diamine, analdehyde, and a compound having an α,β-unsaturated electron withdrawingmoiety. The aldehyde may be a polyaldehyde that is paraformaldehyde. Theproduct may have a cross-linkable polymer. The cross-linkable polymermay be functionalized with at least one of cyanate, alkyne, epoxide,maleimide, and norbornene-2,3-dicarboximide. The cross-linkable polymermay be selected from the group consisting of:

where each instance of ‘Z’ is independently selected from maleimide,norbornene-2,3-dicarboximide, cyanate, alkyne, and epoxide. Themaleimide group, the norbornene-2,3-dicarboximide, the cyanate, thealkyne, and the epoxide may be unsubstituted or substituted with alkylor aryl. Aryl includes phenyl, napthyl, anthracenyl, and pyrenyl. Arylincludes one or more C1-C20 alkyl moieties covalently bonded to one ormore C6-C20 aryl moieties. Alkyl includes C1-C20 alkyl, such as C1-C6alkyl. ‘n’ may be a positive integer, such as from between about 2 toabout 500, such as between about 2 and about 100, such as between about10 and about 50. Maleimide may be of the structure:

norbornene-2,3-dicarboximide may be of the structure:

cyanate may be of the structure:

alkyne may be of the structure:

and epoxide may be of the structure:

In some embodiments, the acceptor of the product is of the structure:

where R is selected from the group consisting of ether, aryl, and alkyl.Ether may be of the structure:

aryl may be of the structure:

and alkyl may be of the structure:

In some embodiments, the diamine of the product is of the structure:NH₂—X—NH₂, where X is a phosphine derivative, ether, or lactone. Thephosphine derivative may be

the ether may be of the structure:

and the lactone may be of the structure:

In some embodiments, a reaction mixture comprises compounds that reactto form a PHT. In some embodiments, the α-terminus and/or ω-terminus ofa diamine reacts with an aldehyde to form an imine intermediate, and theimine intermediate then forms a hexahydrotriazine linkage upon reactionof the imine intermediate with two other imine intermediates present inthe reaction mixture, as shown in Scheme 1. As described herein, anα-terminus and ω-terminus refer to opposing ends of a molecule orpolymer. The reaction of Scheme 1 is typically performed at atemperature above 50° C., such as about 200° C., to form the PHT.

Each instance of ‘X’ independently includes a phosphine derivative,ether, and lactone. In some embodiments, a phosphine derivative isselected from the general structures:

Ether includes arylethers and alkylethers. An arylether may be of thegeneral structure:

such that the diamine is, for example, 4,4′-oxydianiline (ODA).

Lactone includes aryl substituted lactones and alkyl substitutedlactones. In some embodiments, a lactone is a phthalide of the generalstructure:

Diamine monomers, and other reactive monomers described herein, mayserve as reactive diluent(s) for polymerization reactions allowing forsolution processing of oligomers and polymers described herein.Furthermore, oligomers and polymers described herein having —NH₂moieties at the α- and/or ω-termini may also react at the α- and/orω-termini with paraformaldehyde to form an imine capable of forming ahexahydrotriazine linkage. A different carbonyl containing compound(i.e., not paraformaldehyde) may be used in addition to or as areplacement of paraformaldehyde. Carbonyl containing compounds includealdehydes and ketones. As described herein, the term “aldehyde” includesaldehyde monomers and aldehyde monomers that can polymerize to formpolyethers, such as paraformaldehyde. Paraformaldehyde may be added to areaction mixture, where it can decompose in situ into formaldehydemonomers (which have carbonyl moieties). Decomposition ofparaformaldehyde may be promoted by heating the reaction mixture.Aldehydes include formaldehyde, acetaldehyde, and polymerized aldehydessuch as paraformaldehyde. A ketone, such as acetone, may be used insteadof or in addition to an aldehyde.

Conjugate addition is a reaction between a nucleophile (a donor) and anactivated olefin or alkyne functionality (a compound having anα,β-unsaturated electron withdrawing moiety, i.e. an “acceptor”), wherethe nucleophile covalently bonds to a carbon of the activated olefin oralkyne. An olefin or alkyne is considered ‘activated’ if the olefin oralkyne is located adjacent to an electron withdrawing group such as acarbonyl moiety. One way to describe an activated olefin or alkyne is a“compound having an α,β-unsaturated electron withdrawing moiety.”Electron withdrawing moieties include carbonyl, nitro, nitrile, andaryl. In the context of Michael addition, the Michael additionnucleophile is known as a “Michael donor” and the activatedelectrophilic olefin or alkyne is known as a “Michael acceptor”. In someembodiments, a reaction mixture comprises an α,β-unsaturated electronwithdrawing moiety and/or a diamine. In some embodiments, the α-terminusand/or ω-terminus of a diamine is a nucleophile and reacts with compoundcontaining an α,β-unsaturated electron withdrawing moiety to form adiamine-acceptor adduct. Acceptors include acrylates and maleimides ofthe general structure (1):

Acrylate includes diacrylates and triacrylates, such as 1,4-butanedioldiacrylate and trimethylolpropane triacrylate, respectively. ‘R’includes ethers, aryl, and alkyl. Ether includes arylethers andalkylethers. In some embodiments, ether is of the general structure

Aryl includes phenyl, napthyl, anthracenyl, and pyrenyl. In someembodiments, aryl is of the general structure:

Aryl includes one or more C1-C20 alkyl moieties covalently bonded to oneor more C6-C20 aryl moieties. In some embodiments, aryl is of thegeneral structure:

Alkyl includes C1-C20 alkyl, such as C1-C6 alkyl. Alkyl may be of thestructure:

Subsequent reaction of the α-terminus (—NH₂) and/or ω-terminus (—NH₂) ofthe diamine-acceptor adduct with additional acceptors and additionaldiamines forms a poly(amine-imide) oligomer. The poly(amine-imide)oligomer may further react with additional acceptors and additionaldiamines to form a poly(amine-imide) copolymer. For example, each of theα- and ω-termini of a diamine may react with an acceptor, such as adiacrylate or a maleimide of general structure (1), to form apoly(amine-imide) copolymer, as shown in Scheme 2.

‘X’ is as described for the diamine of Scheme 1. ‘R’ is as described forthe maleimide of general structure (1). Furthermore, the α-terminus(—NH₂) and/or ω-terminus (—NH₂) of a poly(amine-imide) oligomer orcopolymer may react with paraformaldehyde to form an imine capable offorming a hexahydrotriazine linkage in the reaction mixture to yield acopolymer. Other oligomers and polymers described herein having —NH₂moieties at the α- and/or ω-termini may also react at the α- and/orω-termini with an acceptor monomer, oligomer, or polymer.

In some embodiments, maleimides described herein are formed in situ byreacting an anhydride with an amine in a reaction mixture. For example,ethylene glycol bis(trimellitic anhydride) and4,4′-(1,4-phenylenediisopropylidene)bisaniline are added to a reactionmixture to form a polyimide. Furthermore, an anhydride may alsoself-polymerize to form a polyanhyride upon curing.

In some embodiments, an acceptor, such as a diacrylate or a maleimide ofgeneral structure (1), self-polymerizes, such as by radicalself-polymerization, to form a self-polymerized acceptor.Self-polymerization of a maleimide of general structure (1), forexample, yields a polyimide of general structure

In some embodiments, one or more of the carbon-carbon double bonds atthe α,ω-termini of the self-polymerized polyimide may be (1) saturated(e.g., hydrogenated) or (2) unsaturated where the carbon-carbon doublebond is an electrophile for subsequent substitution with a diaminemonomer, oligomer, or polymer described herein to form a copolymer. Inother words, the unsaturated α,ω-termini of a polymerized polyimide maybe “acceptor” moieties in that they have an α,β-unsaturated electronwithdrawing moiety.

In some embodiments, a reaction mixture comprises one or morecross-linkable polymers, such as linear cross-linkable polymers. Asdescribed herein, a cross-linkable polymer includes polymers having (1)a backbone comprising aryl moieties and (2) reactive moieties at theα,ω-termini and, in some embodiments, reactive moieties along thepolymer backbone. The reactive moieties at the α,ω-termini of the one ormore cross-linkable polymers may be an acceptor (as describedpreviously), an epoxide, an ethylene, and/or a cyanate. A cross-linkablepolymer may react to form a fully or partially cross-linked polymer. Across-linkable polymer includes general structures (2), (3), and (4):

where each instance of ‘Z’ is independently selected from a maleimidesuch as

a norbornene-2,3-dicarboximide such as

a cyanate such as

an alkyne such as

and an epoxide such as

In some embodiments, a cross-linkable polymer is an epoxide or issubstituted with an epoxide that is a diglycidyl ether, such as adiglycidyl ether of a bisphenol, such as bisphenol A. In embodimentswhere the one or more cross-linkable polymers is substituted with amaleimide or norbornene-2,3-dicarboximide, the maleimide andnorbornene-2,3-dicarboximide can each be an acceptor where thecarbon-carbon double bond is an electrophile for substitution with adiamine, such as the diamines shown in Scheme 2, diamine oligomers, ordiamine polymers, to form a fully or partially cross-linked copolymer.Alternatively or in addition, the maleimide andnorbornene-2,3-dicarboximide may self-polymerize with othercross-linkable polymers substituted with maleimide ornorbornene-2,3-dicarboximide, respectively, to form self-polymerizedcross-linked polymers that are each a self-polymerized polyimide.

In embodiments where the one or more cross-linkable polymers issubstituted with an epoxide, the epoxide may be an electrophile forsubstitution with a diamine, such as the diamines shown in Scheme 2,diamine oligomers, and/or diamine polymers to form a poly(aminoalcohol)polymer.

In embodiments where the one or more cross-linkable polymers issubstituted with a cyanate or alkyne, the cyanate and alkyne allowself-polymerization to form self-polymerized cross-linked polymers.Self-polymerization of cyanates and alkynes does not interact with otherPHT network forming reactions in a reaction mixture, e.g. the reactionswith diamine monomers, diamine oligomers, and/or diamine polymers.Self-polymerization of cyanates and/or alkynes in a reaction mixturecontaining one or more of other reaction products (e.g. reactions withdiamines) yields a product blend where the morphology is controlled bykinetic quenching of the reactions occurring of a reaction mixture. PHTnetwork forming reactions that do not interact with other PHT networkforming reactions allows for a systems chemistry approach to polymerproduct formation where the reaction mixture forms a product thatbecomes increasingly viscous as the two or more reactions are occurringin the reaction mixture/product to a point where viscosity is such thatfurther reactions with monomers, oligomers, and/or polymers arekinetically quenched, i.e. subsequent reaction of monomers, oligomers,and polymers in the reaction mixture/product substantially or completelyterminates. Kinetic quenching of a reaction mixture allows for reducedbiphasic separation of a multicomponent product.

Furthermore, co-polymerization and/or self-polymerization of a reactionmixture can be tuned by a cure temperature of a reaction mixture andvolume fraction of the starting materials in the reaction mixture toenable further control of the properties of a resulting product. Forexample, a cure temperature may be such that a first co-polymerizationand/or a first self-polymerization occur in a single vessel and theviscosity of a resulting product increases (vitrification) as thereactions progress, resulting in substantial or complete termination offurther co-polymerization and/or self-polymerization. In someembodiments, curing at a temperature above about 150° C., such asbetween about 200° C. and about 250° C., such as about 175° C., promotesself-polymerization of a conjugated molecule, such as an acceptor.Curing temperatures above 150° C. also promote solvent removal, if asolvent is present. Controlled vitrification of products describedherein allows for products, such as thermosets, with decreased storagemodulus (G′) as compared to a thermoset containing exclusively PHTpolymers. Controlled vitrification of thermosets described hereinfurther allows for products that exhibit specific melt and or glasstransitions (such as above 150° C., such as between about 190° C. andabout 210° C.).

In some embodiments, products may be applied to a substrate, such as ametal screen, by dipping a substrate into a solution containing startingmaterials followed by curing. Products may also be applied to asubstrate by spray-coating a substrate with a solution containingstarting materials followed by curing. Curing temperatures may bebetween about 50° C. and about 250° C., such as about 150° C. and about225° C., for example 200° C. Curing promotes polymer formation anddispersal of starting materials in an increasingly vitrified product. Insome embodiments, a diamine is present in a reaction mixture from about1 v/v % to about 99 v/v %, about 10 volume % (v/v %) to about 90 v/v %,such as about 25 v/v % to about 75 v/v %, such as about 40 v/v % toabout 60 v/v %. In some embodiments, a Michael acceptor is present in areaction mixture from about 1 v/v % to about 99 v/v %, about 10 volume %(v/v %) to about 90 v/v %, such as about 25 v/v % to about 75 v/v %,such as about 40 v/v % to about 60 v/v %. In some embodiments, across-linkable polymer is present in a reaction mixture from about 1 v/v% to about 99 v/v %, about 10 volume % (v/v %) to about 90 v/v %, suchas about 25 v/v % to about 75 v/v %, such as about 40 v/v % to about 60v/v %.

EXAMPLES

Tg values were determined by differential scanning calorimetry (DSC).Total heat flow may be separated into reversing and nonreversingcomponents. The reversing signal contains heat capacity related eventssuch as the glass transition and may be expressed as “reversing heatcapacity” (Rev Cp). DSC analyses were performed on a TA InstrumentsQ2000. The samples (5 to 7 mg) were scanned from −80° C. to 250° C. at a5° C./min heating rate in aluminum closed pans.

Example 1

0.2 g ODA (1 mmol), 0.057 g paraformaldehyde (1.9 mmol, 1.9 eq.), 0.1 g1,1′-(methylenedi-4,1-phenylene)bismaleimide (0.28 mmol, 0.28 equiv.)and 1.5 mL N-methyl pyrollidone (final weight concentration=0.24 g/mL)were weighted out in a 3-dram vial equipped with a stir bar. The vialwas capped and transferred into a 50° C. sand bath. After approx. 15min, the solution became clear. After another 3 h, the solution wasdeposited on a glass microscope slide with aluminum tape (80 μmthickness) boundaries using a glass pasteur pipet. The following thermaltreatment was used: 50° C. for 1 h, 50° C. to 110° C. over 1 h, 110° C.for 1 h, 110° C. to 200° C. over 1 h, 200° C. for 1 h after which thefilm was allowed to cool down to room temperature. The aluminum tape wascarefully peeled off the slide and the film was floated from the glassplate by soaking in deionized water. The film was next rinsed withacetone and dried in a vacuum oven overnight. TGA: T_(5%)=245° C. DSC:T_(g)=186° C.

FIG. 1 is a graph, hereinafter referred to as “Graph 1”, illustratingrelative glass transitions (reversing heat capacity) obtained aftercuring the films at 200° C. Percentages of maleimide are weight % ofmaleimide starting material relative to weight % ODA in a startingcomposition before curing. Amounts of paraformaldehyde are adjustedrelative to initial amounts of maleimide/ODA.

As shown in Graph 1, each film has a single Tg and each Tg is betweenthe Tg of the pure ODA/bismaleimide resin (Tg=210° C. at “100%”) and thepure ODA/paraformaldehyde PHT resin (Tg=190° C., not shown). Therefore,the bismaleimide/ODA (with self-polymerized bismaleimide) andODA/paraformaldehyde resins are intimately mixed and the Tg of theoverall material can be adjusted by adjusting the initial ratio ofreagents.

Example 2

0.2 g ODA (1 mmol), 0.056 g paraformaldehyde (1.9 mmol, 1.9 eq), 0.1 gdiglycidyl ether of bisphenol A (0.3 mmol, 0.28 equiv.) and 1.5 mLN-methyl pyrrolidone (final weight concentration=0.24 g/mL) wereweighted out in a 3-dram vial equipped with a stir bar. The vial wascapped and transferred into a 50° C. sand bath. After approx. 15 min,the solution became clear. After another 5 min, the solution wasdeposited on a glass microscope slide with aluminum tape (80 μmthickness) boundaries using a glass pasteur pipet. The following thermaltreatment was used: 50° C. for 1 h, 50° C. to 110° C. over 1 h, 110° C.for 1 h, 110° C. to 200° C. over 1 h, 200° C. for 1 h after which thefilm was allowed to cool to room temperature. The film couldn't bepeeled off by floating technique in deionized water and had to bescraped off of slide using a razor blade. TGA: T5%=280° C. DSC: Tg=147°C.

Example 3

0.2 g ODA (1 mmol), 0.1 g paraformaldehyde (3.3 mmol, 3.3 eq), 0.1 gpolyimide of ethylene glycol bis(trimellitic anhydride) and4,4′-(1,4-phenylenediisopropylidene)bisaniline (approx. 5 mmol) and 1.6mL N-methyl pyrrolidone (final weight concentration=0.25 g/mL) wereweighted out in a 3-dram vial equipped with a stir bar. The vial wascapped and transferred into a 50° C. sand bath. After 1 h, the solutionwas filtered through a 0.2 mm glass fibers filter and deposited on aglass microscope slide with aluminum tape (80 μm thickness) boundariesusing a glass pasteur pipet. The following thermal treatment was used:50° C. for 1 h, 50° C. to 110° C. over 1 h, 110° C. for 1 h, 110° C. to200° C. over 1 h, 200° C. for 1 h after which the film was allowed tocool to room temperature. The aluminum tape was carefully peeled off theslide and the film was floated from the glass plate by soaking indeionized water. The film was next rinsed with acetone and dried in avacuum oven overnight. TGA: T5%=253° C. DSC: Tg=157° C.

FIG. 2 is a graph, herein after referred to as “Graph 2”, illustratingrelative glass transitions (reversing heat capacity) obtained aftercuring the films at 200° C. Percentages shown are weight % of (ethyleneglycol bis(trimelliticanhydride+4,4′-(1,4-phenylenediisopropylidene)bisaniline) relative toweight % ODA in a starting composition before curing. Amounts ofparaformaldehyde are adjusted relative to initial amounts ofODA/(ethylene glycol bis(trimellitic anhydride4,4′-(1,4-phenylenediisopropylidene)bisaniline).

As shown in Graph 2, each film has a single Tg and each Tg is betweenthe Tg of the pure ODA/(ethylene glycol bis(trimelliticanhydride+4,4′-(1,4-phenylenediisopropylidene)bisaniline) resin (Tg=210°C. at “100%”) and the pure ODA/paraformaldehyde PHT resin (Tg=190° C.,not shown). Therefore, the ODA/(ethylene glycol bis(trimelliticanhydride+4,4′-(1,4-phenylenediisopropylidene)bisaniline)(withself-polymerized bismaleimide) and ODA/paraformaldehyde resins areintimately mixed and the Tg of the overall material can be adjusted byadjusting the initial ratio of reagents.

Overall, a systems chemistry approach may be used to synthesize PHTproducts that achieve tunable material properties such as yieldstrength, char yield, and thermal response. A systems chemistry approachfurther allows the combination of two materials with differentproperties in order to prepare a single material with the properties ofits two constituting components in a reactive blending approach. Asystems chemistry approach allows for access to tunable propertiesthrough the directed application of isolated chemical reactions,simultaneously in a single vessel. A systems chemistry approach allowsmitigation of some of the challenges for recyclable high-performancehexahydrotriazines conveniently by incorporating functional groups thathave the desired material properties in a single step through judiciouschoice of polymers and/or co-polymers based on reactivity. For example,self-polymerization of cyanates and/or alkynes in a reaction mixturecontaining one or more of other reaction products (e.g. reactions withdiamines) yields a product blend where the morphology is controlled bykinetic quenching of the reactions occurring in a reaction mixture.Kinetic quenching of a reaction mixture allows for reduced biphasicseparation of a product. Furthermore, co-polymerization and/orself-polymerization of a reaction mixture can be tuned by a curetemperature of a reaction mixture and volume fraction of the startingmaterials in the reaction mixture to enable further control of theproperties of a resulting product.

The present disclosure has been presented for purposes of illustrationand description, but is not intended to be exhaustive or limited to theembodiments in the form disclosed. Many modifications and variationswill be apparent to those of ordinary skill in the art without departingfrom the scope and spirit of the embodiments. The embodiments werechosen and described in order to best explain the principles of theembodiments and their practical application, and to enable others ofordinary skill in the art to understand the embodiments.

What is claimed is:
 1. A product that is the reaction product of: adiamine; an aldehyde; and a compound having an α,β-unsaturated electronwithdrawing moiety.
 2. The product of claim 1, wherein the aldehyde isparaformaldehyde.
 3. The product of claim 1, wherein the compound havingan α,β-unsaturated electron withdrawing moiety is

wherein R is selected from the group consisting of ether, aryl, andalkyl.
 4. The product of claim 3, wherein the ether is

the aryl is

and the alkyl is


5. The product of claim 1, wherein the diamine is of the structure:NH₂—X—NH₂, wherein X is selected from the group consisting of aphosphine derivative, an ether, and a lactone.
 6. The product of claim5, wherein the phosphine derivative is

the ether is

and the lactone is


7. The product of claim 1, wherein the product comprises apolyhexahydrotriazine including the structure:

wherein each instance of X is independently a phosphine derivative,ether, or lactone.
 8. The product of claim 7, wherein the productfurther comprises: the structure

wherein R is selected from the group consisting of an ether, an arylgroup, and an alkyl group, wherein X is selected from the groupconsisting of a phosphine, an ether, and a lactone, and wherein n is apositive integer.
 9. The composition of claim 8, wherein R is selectedfrom the group consisting of ether of structure

aryl of structure

and alkyl of structure:


10. The composition of claim 9, wherein n is a positive integer frombetween about 2 to about
 500. 11. The composition of claim 8, wherein Ris ether.
 12. The composition of claim 8, wherein R is aryl.
 13. Thecomposition of claim 8, wherein R is alkyl.
 14. The product of claim 7,wherein the product further comprises: the structure

wherein R is selected from the group consisting of ether, aryl, andalkyl, and wherein n is a positive integer.
 15. The composition of claim14, wherein R is selected from the group consisting of ether ofstructure

aryl of structure

and alkyl of structure:


16. The composition of claim 15, wherein n is a positive integer frombetween about 2 to about
 500. 17. The composition of claim 14, wherein Ris ether.
 18. The composition of claim 14, wherein R is aryl.
 19. Thecomposition of claim 14, wherein R is alkyl.
 20. The product of claim 1,wherein the product comprises: the structure

wherein R is selected from the group consisting of an ether, an arylgroup, and an alkyl group, wherein X is selected from the groupconsisting of a phosphine, an ether, and a lactone, and wherein n is apositive integer.